It is known that ultrasonic vibrations can be used to clean and help sterilize soft contact lenses. Firstly an ultrasonic device is used to produce sound frequency vibrations which are then transmitted into a tank means containing soft contact lenses and lens cleaning fluid and the contact lenses appear to remain virtually stationary.
The ultrasonic device generates an unseen wave of highly accelerated cleaning molecules which continuously bombard the lens surface. The contact lenses do not appear to move, nevertheless, an imperceptible scrubbing action is created which helps to remove proteins, mucins and other deposits from the lens surface. GB-A-1484945 discloses such a device which also uses heat disinfection to complete the process. However such a process is fairly time consuming and the device may prove too costly for general public use.
Electro-mechanical means may be used to produce high energy vibrations which can be employed to much the same effect as sound vibrations in an ultrasonic device. The high energy device once again transmits its vibrations into tank means. This generates an unseen wave of cleaning molecules to clean the surface of the lens. As one can observe, the lens cleaning fluid and the contact lenses will appear to remain virtually stationary throughout the entire process. Although such a device would be less expensive to produce, the cleaning time will still be relatively long such as 12-13 minutes. There is also a question as to whether such subtle devices can successfully remove dirt and other foreign bodies adhering to the lens.
The present invention provides a convenient, safe, but more important, quick and effective method of cleaning contact lenses. There is provided a cleaning apparatus for cleaning contact lenses, comprising an electrically operated motor, a support arm, vibration generating means operating within a frequency range of 10 to 100 Hz, preferably 20 to 45 Hz, more preferably 35 to 45 Hz, and tank means for receiving contact lens fluid. A contact lens holder receives the contact lenses and communicates with the tank means to enable unimpeded transfer of cleaning fluid therebetween. The holder is directly coupled to the motor by means of the support arm which is drivable by the motor to impart reciprocating motion to the holder in a rotational or linear sense. The vibration generating means, is operable during the reciprocating motion such that vibration is imparted to the contact lenses simultaneously with the reciprocating motion.
In one embodiment, the electric motor will provide a linear reciprocating agitation at its output. The agitation may be slow or a rapid movement thus a rheostat or speed control may be comprised in the cleaning apparatus. The motion in the tank means, whether linear, i.e., side to side or rotary, causes the contact lenses to move about and wash themselves automatically in the lens cleaning fluid.
Conveniently, said tank means define a pair of discrete tanks, each for receiving an individual contact lens. Alternatively, there may be a single tank chamber divided into two separate regions or with two central perforated baskets each of which is to hold an individual contact lens. A sponge or polystyrene attachment may be present in the tank means such that an abrasive rubbing action will be imparted to the contact lenses whilst the machine is in operation. A heating element may also be present in the tank means to provide heat disinfection once the lenses have been cleaned.
The process hereby disclosed is particularly advantageous to people with busy schedules as the process may be achieved in about 30 to 60 seconds when operating at a vibrational frequency of 20 to 45 Hz. An operating frequency of 35 to 45 Hz is most preferred.
The apparatus comprises tank means for receiving at least one lens, said tank means defining a discrete region for receiving each lens. With a lens disposed in such a region and an appropriate cleaning fluid in the tank means, thorough cleaning of the lens is effected.
Preferably, said electrical agitating means is adapted to be powered by an A.C. mains supply for which purpose it incorporates a transformer and a rectifier. The transformer automatically responds to the level of the power supply and regulates the supply of power to the electrically operated motor accordingly, so as to provide the correct level of voltage to the electrical motor or rechargeable battery. This will enable the apparatus to be used either with a 110 volt A.C. supply or a 210-240 volts A.C. supply.
Conveniently said tank means are removably mounted upon a drive output from the electrically operated motor.
Alternatively to powering the motor from a mains supply, said electrical agitation means may be adapted to be powered by a battery thus enabling its use remote from a power supply.
The battery may be rechargeable and may be adapted to be recharged, with rectification, via said transformer.
Preferably, said electrical agitating means includes a timer such that the motor operates for a predetermined length of time after being switched on before being switched off automatically.
The present invention also provides a method for cleaning at least one contact lens, said method comprising the steps of charging lens receiving tank means with contact lens cleaning fluid, inserting said at least one contact lens into the cleaning fluid, supporting the tank means on a support arm drivable by an electrically operated motor to subject the at least one contact lens to reciprocating motion in a rotational or linear sense, imparting vibration to the at least one contact lens at a frequency of 10 to 100 Hz, preferably 20 to 45 Hz, more preferably 35 to 45 Hz, simultaneously with said reciprocating motion thereby to effect cleaning of the at least one lens. Subsequently, removing each lens from the tank means.
Said method may comprise the additional step of sealing the tank means after insertion of the lenses into the cleaning fluid prior to agitating the tank means.
The electrically operated motor providing agitation may, for example, comprise an electric arrangement or a cam arrangement or may comprise a coil supplied with an A.C. current and a core which is sequentially attracted to and repelled by the coil as the flow of current is repeatedly reversed. In any event the agitator provides a reciprocating action. This reciprocating action is transferred to the tank means and thus will shake the tank means and the contents thereof vigorously.